The Newcastle NHS Chronic Fatigue Syndrome Service: not all fatigue is the same

Authors

Institution

Introduction

In England the Department of Health has funded specialist clinical services aimed at diagnosing and managing the symptoms of chronic fatigue syndrome (CFS). These services are not available to those who do not fulfil the diagnostic criteria for CFS. This service evaluation examined the proportion of those referred to a specialist CFS service fulfilling the Fukuda diagnostic criteria for CFS and the alternative fatigue-associated diagnoses.

Methods and Results

The CFS database was interrogated to include every patient referred to the Newcastle service from November 2008 to December 2009. All medical notes were reviewed and the diagnosis, sex and age recorded. Data were compared to a previous service evaluation (2005–07). In 2008–09, 260 subjects were referred: 19 referrals per month (260/14), compared with 17 referrals per month in 2005–07 (375/24). The proportion of patients diagnosed with CFS increased significantly compared with 2007 (36% [20/56] vs 60% [157/260]; p<0.0001). Of the 40% of patients subsequently found not to have CFS the most common diagnosis was fatigue associated with a chronic disease (47% of all alternative diagnoses); 20% had primary sleep disorders, 15% psychological/psychiatric illnesses and 4% a cardiovascular disorder. Thirteen per cent remained unexplained (5.2% of the total referrals).

Conclusions

This study found a significant increase in the proportion of patients referred to National Health Service (NHS) CFS services diagnosed with CFS. A large proportion of patients presenting with fatigue are not eligible for referral to the Department of Health specialist fatigue services, which represents an unmet need in terms of symptom management in current NHS services.

Publication

Comment by ME Research UK

At present, there are many ways of diagnosing ME, CFS, CFIDS, CFS/ME and ME/CFS – and just listing these acronyms illustrates the confusion that besets the field. Yet each new definition delivers only a “diagnosis of exclusion” of other conditions, based on clusters of vaguely defined symptoms shared with other illnesses. How valid a diagnosis of ME/CFS really is depends critically on the rigour of the initial clinical assessment, and the efforts expended to exclude other treatable conditions that might be causing the collection of symptoms.

The clinical guideline produced by the UK’s National Institute for Health and Clinical Excellence (NICE) in 2007 came up with its own variant of diagnostic criteria for “CFS/ ME” – new, unexplained, persistent/recurrent fatigue with a post-exercise component plus one or more of a range of common symptoms such as difficulty with sleeping, muscle and/or joint pain and headaches. It is also recommended that patients be referred to specialist ME/CFS clinical services. Such broad-brush criteria, combined with the lack of GP education about ME/CFS, have led to concerns about the application of the guideline in the surgery or clinic.

Fortunately, this study by Professor Julia Newton and colleagues has opened a window into the appropriateness of referrals to one ME/CFS service. The team examined the records of every patient referred to the Newcastle CFS/ME Clinical Service between November 2008 and December 2009. Each patient had complete data on the UK national minimum dataset, a standard ME/CFS assessment tool, from which the diagnosis could be checked. Looking at the results, Professor Newton found that 260 patients had been referred to the clinical service in 2008 and 2009 (approximately 19 referrals per month). Interestingly, the proportion of patients found to be correctly diagnosed with ME/CFS by the Newcastle service increased significantly compared with the results of a previous service audit in 2007 (60 versus 36%, respectively), a finding which might suggest that the introduction of the NICE clinical guideline in 2007 had somewhat improved the correct identification of these patients by GPs.

However, the most important finding was that 103 (40%) of patients seen by the Newcastle Service could in fact be diagnosed with other conditions. The most common alternative diagnosis in these patients was fatigue associated with a chronic disease (47% of all alternative diagnoses). The next common alternative diagnosis was primary sleep disorder (20%), including 8 patients with obstructive sleep apnoea and 12 with another primary sleep disorder – an important finding since sleep disorders form a significant and potentially treatable diagnostic group. Furthermore, 15% of all alternative diagnoses were psychological/psychiatric illnesses (most commonly, depression, anxiety and post-traumatic stress disorder); 13% were “unexplained” but not ME/CFS (5.2% of total referrals); and 4% were cardiovascular disorders (vasovagal syncope in patients with fatigue symptoms, who also had a history of episodes of loss of consciousness, with the diagnosis made after a reproduction of symptoms in head-up tilt testing).

Professor Newton’s results concur with those from two smaller service audits (Dundee 1993 – see abstract below; and Newcastle 2007 – see report of Dr Gavin Spickett’s talk to the ME Research UK Cambridge conference in 2008), and reiterate that a significant minority of UK patients referred from primary care with a diagnosis of ME/ CFS can receive alternative, exclusionary diagnoses if investigated at a specialist clinic. And they illustrate that in the absence of a full clinical assessment (which most patients in the community have either never undergone, or last had many years ago), the diagnosis of ME/CFS can easily become a stopping-off point for clinically complex patients with a variety of different illnesses.

This problem is encountered not only in the UK. A fascinating commentary in 2008 in Minnesota Medicine (available online) described the difficulties experienced at a clinic in the USA for patients with fatigue, exercise intolerance and weakness (i.e., patients very like ME/CFS patients in the UK). After reporting on three paediatric cases (all of whom received serious, new diagnoses), the authors commented that, “a thoughtful and thorough physical exam can sometimes reveal otherwise hidden diagnoses”. Commentaries like this, and investigations like this one at Newcastle, certainly raise the question of which treatable diagnoses might be uncovered if all patients currently parked in the ME/CFS diagnostic layby were examined intensively at a specialist Centre of Excellence by thoughtful and thorough physicians.

The ideal would be for ME/CFS or the subtypes within to be diagnosed objectively with criteria based on clinical or laboratory measurements. Illnesses are most easily accepted when they have a specific clinical or scientific “signature”, such as a biochemical test and/or a cluster of specific signs, which establishes diagnostic validity and confers legitimacy in the eyes of healthcare professionals. The discovery of such a signature specific for ME/CFS would transform the outlook for patients.

Post-Viral Fatigue Syndrome sometimes called CFS (PVFS) is a recognised syndrome characterized by relapsing fatigue lasting six months or more in which other illnesses have been excluded. Associated symptoms include mild fever, sore throats, lymphadenopathy, muscle weakness, post-exercise fatigue, headache, a range of neuropsychological symptoms including memory loss and inability to concentrate as well as sleep disturbance. PVFS is becoming a more common reason for referral to both General Medical and Rheumatology Outpatient clinics due to its chronic nature and rheumatic symptoms. An audit study was designed to examine correctness of GP diagnosis and usefulness of outpatient screening. We examined 100 consecutive referrals to the Outpatient clinic from August 1990 to June 1992 inclusive. All patients studied had been diagnosed by the general practitioner as PVFS. The patients were then assessed and the diagnosis of PVFS confirmed if the patients met the classic case definition of CFS (Rev Infect Tis 1991; 13 (Suppi 1): 53-55. 107 diagnoses were made in 100 serially screened patients. 67% fulfilled the criteria for PVFS, 12% were diagnosed as having a psychiatric disorder alone, 7% met the criteria of flbromyalgia and there were 21 other organic diagnoses. The organic diagnoses made included muscle disease, connective tissue diseases and endocrine disorders. There was one patient found to have a brain tumour and one patient found to have HIV infection. In conclusion, therefore, there was a 20% incidence of organic pathology in this series, 7% incidence of fibromyalgia and 12% incidence of psychiatric disease.